1. Field of the Invention
The present invention relates to a projection image display apparatus and, more particularly, is suitable for use in cooling a light source and the like by means of a coolant.
2. Description of the Related Art
In a projection image display apparatus (hereinafter referred to as “projector”), it is needed to efficiently remove heat generated by a light source and the like. Conventionally, the heat removal has been mainly carried out by air cooling with a fan or the like. Meanwhile, in response to recent requests for higher brightness, a light source has come to contain multiple lights, resulting in a need for more cooling efficiency. In using a solid light source such as a semiconductor laser as a light source, in particular, output of laser light is prone to fluctuate with temperature changes. Therefore, there is demand for more cooling efficiency increases and stricter temperature control.
According to the demand, a cooling method using a coolant can be used. The use of a coolant raises cooling efficiency as compared to the case with air cooling. Accordingly, it is possible to carry out heat removal and temperature control on a semiconductor laser smoothly and efficiently. The use of a coolant also decreases the number of fans as compared with air cooling, thereby reducing noise from a projector. Moreover, a coolant can be used to cool a liquid crystal panel. In the case of cooling with a coolant as above, it is necessary to pay attention to safety against leakage of the coolant.